Rust Runs on EVERYTHING, Including the Arduino | Adventures in Embedded Rust Programming 

I just watched this and spat out my coffee XD I have no idea.

Muscle memory

@@nodge9671 Not a real thing

Blew my fkn mind

@@milespiano ??? XD

Also binary size. For microcontrollers, flash space is critical.

@@cerulity32k yeah he even mentioned that he said "600k wow pretty big" yeah cause it's got all the debug hooks lmao

Good to know, thank you!

Yeah I found the project setup pretty clumsy. Luckily Rahix has a template you all can use for your projects.

I generally agree with this comment. There’s just not as much polish here as there is with other areas of rust. None of the knowledge is all in one place. That’s why I’m so excited for LLL (or L3?) to take on this topic. He’s clearly a bright guy good at explaining things, including the dusty corners.

I'm already glad it's this much clearer. While doing the Rust embedded book in 2019, there was a lot more things to get a hold of. Like for instance the STM32F303 board. Now I can just grab an Uno or Nano that I have lying around and actually use. The source code has also gotten a lot more compact.

The Knurling Project is actually pretty hot. It kind of gives you "compile", "flash", "debug", "forward log/output" and other things out of the box. It still does require an understanding of how embedded rust works in general, of course.

Just wondered how Rust would work on AVR (As the CPU is not into the LLVM of the Rust compiler) only ARM-Cortex etc is.

@@HermanWillems Rust works on AVR, but as far as I know it uses some parts from the AVR GCC toolchain. At least the linker

Arduino is just a a collection of libraries and a simple IDE, like a sandbox for beginners. Of course Arduino didn't make AVR, they're just using the old chip on their branded PCBs

Thank you, this was my main question watching the video in 2023 :)

I agree. The title really confused me. Rust isn't a supported target on all the platforms we use at my job.

I don't know much about Rust, but isn't one big advantage that Rust will not have Runtime Errors. All errors are handled by the compiler. Leaves only errors in logic. But in embedded that seems like a big advantage to me, because runtime errors are hard to track afterwards.

C is your best choice.

@@erikjvanderveen That is just factually incorrect mate what do you think the panic handler is for?

@@zaper2904I was just echoing what I heard in previous video on Rust. Stating that one of the advantages of Rust compared to C(++) would be that it would be nearly impossible to write code that would give a runtime error. How this would be achieved, I don’t know. If you say there is a panic handler, then obviously it’s eiter a useless thing, or it’s there to handle runtime errors. I guess you might just be right. Maybe if there comes a time that I will learn Rust, I will find out. For now I’m to busy writing c# and typescript professionally and doing some c(++) for hobby

@@erikjvanderveenDiv by zero? Just to name one very obviously possible one.

And for sake of completeness the time it takes to actually write the code as far as programmer time. Because I think you’ll find you will get fairly close to rust for an order of magnitude less time writing it.

I think benchmarking battery or memory consumption would be a more fitting benchmark. You're rarely ever going to need performance on these chips, if you're driving them to the limit and not currently revising a cheaper version of a well sold device you're probably doing it wrong - and at that point you can afford to rewrite it in assembly or whatever if you need it. Most of the time at worst you send updates a little slower, who cares. Meanwhile running out of memory is a real issue, and if you're trying to run devices on battery, or generally around the clock, energy consumption is very relevant.

@@9SMTM6 I think performance should work as a good proxy for battery usage. Generally speaking, if your code isn't running, the processor can idle/sleep/standby/etc. So that would be a major power savings. Your memory usage comment is 100% accurate. That is the real killer on embedded.

@@brendanhansknecht4650 probably not the worst, but also not necessarily a perfect indicator, especially with multicore - like the RPi Zero 2 has. But also memory usage tends to influence energy consumption, and unfortunately often not in a linear fashion. Also thinking about it, I think it's easier to measure, well not necessarily battery life, but energy usage correctly and in a realistic environment. For speed though it's harder to measure and might push one to unrealistic scenarios to measure a difference at all.

@@brendanhansknecht4650 lol try to compare the performance and current for AVR and a simple cortex M0 and you'll have a bad time

Glad you enjoy it!

Thanks a ton!

Yup! When you use the Arduino bootloader instead of the ICSP, it doesn’t touch the bootloader section.

Can you please share pointers on how to?

I'm guessing you'd add something to the toml file?

and also that using [no_std] means you cannot use 90% of the libraries you may be used to.

I guess he has beefed up his readme since I played with it last.

Thanks!

Exactly! AVRDUDE isn't taking the whole ELF and stuffing it in there, only the necessary program memory.

I have the same problem.. Can you compile your project now?

For anyone wondering I have solved the error 'eh_personality'.. You need to put these lines in your cargo.toml: [profile.dev] panic = "abort" [profile.release] panic = "abort"

I'm not exactly an expert on embedded, but this sounds very wrong to me. I've admittedly only coded in one "higher-level" language for controllers, that being Micropython, but that one was already showing me the limits. You barely ever have any bindings for compatible libraries (which you need to drive sensors or even networking), and I ran out of memory fast. Python pushes you to a model that is resource intensive. Of you can't find a fitting library with binding for your device you need to use a C library. Rust can do that just fine and easily, Python, and I'm certain most other comparable languages, make that painful. As I said I've got limited experience, but from what I've seen, Rust as a basic language is PERFECT for embedded. Because of no GC or pervasive reference counting it has basically the same memory footprint as C, which is good on memory starved embedded devices (memory costs energy and money... Disproportionately much on embedded). Rust doesnt use exceptions, like C++, but an explicit error model, which can actually run without a heap, and which also means far less debugging, because it's explicit and thus always well documented and easy to spot. Rust has an ecosystem of packages on crates.io that run on "no_std" environments, which is pretty much a necessity on embedded. And because if it's expressive type system libraries have much less gotchas than your typical C library. Even your typical device manufacturer will have a hard time to code a difficult to use Iibrary:).

Luckily the whole ELF doesn’t get flashed to the board. Most of that 600Kb is ELF header and debug symbols. AVRDUDE rips out only programmable pages from the ELF and puts them on the AVR.

Thank you!

What? How is that even relevant?

Thank you! Cheers!

Not really, I didn't go into the release vs debug for the sake of this video. Wouldn't hurt to do a release!

I do wonder what size the binary would be stripped.

@@Dygear it's 324 bytes for me when building in release. So very reasonable size.

@@brendanhansknecht4650 Wow! That really good!

To clear up your confusion 4 months later, it's just that this youtuber forgot to create a release build and to strip the binary.

LOL! Yeah, it was pretty clumsy to get the cargo set up. I highly suggest using the template crate in the description.

@@LowLevelLearning I highly suggest to use C or Assembler in this case :D

Nearly 6000 bytes where the Arduino uses around 1000. Seems a tad on the big side to me . Assemnly can do it in 28 bytes! ;-) Still, an interesting series so far, thanks. Cheers, Norm.

No need to XOR. Just write to the PINx register instead of the PORTx register and it will toggle. Cheers, Norm.

@@NormanNodDunbar as far as I’m aware there’s no pin operation in avr assembly. There’s just an out opcode that takes a port and a value. Even the sbi and cbi operate on a whole port. It wouldn’t be very RISC if there was either :) Or am I missing something?

It might do less allocations when you specify no_std... but yeah, it could absolutely cause problems on some small devices.

Not judging, just found it interesting.

Perhaps if you are making more complicated program and want rusts memory safety features. Or if you are comfortable with rust but not C.

rust seems like c with safety wheels attached. It probably is much slower

Rust can be just as fast as c if not faster. Basically its around the same speed depending on application and implementation. Most of rusts checks happen at compile time.

@@mychromebook9935 What? You haven't really done anything with Rust, have you?

The runtime performance is same as C or C++. Very often the same exact machine instructions. Memory safety comes from what the compiler refuses to build, not from additional runtime checks.